ASE G1 Auto Maintenance and Light RepairEngine SystemsEasy

A technician is diagnosing a vehicle that exhibits a strong odor of gasoline, particularly after the engine has been running. Upon inspection, the technician notices a wet spot on the ground directly below the fuel tank. Which of the following is the most likely cause?

  1. AA faulty oxygen sensor
  2. BA clogged fuel filter
  3. CAn inoperative fuel gauge sender
  4. DA leaking fuel line or fuel tank
Show answer & explanation

Correct answer: D. A leaking fuel line or fuel tank

A strong gasoline odor and a wet spot under the fuel tank are direct indicators of a leak in the fuel delivery system, most commonly a fuel line or the tank itself.

Why the other options are wrong

  • A. A faulty oxygen sensor affects fuel-air mixture and emissions, not external fuel leaks.
  • B. A clogged fuel filter would typically cause engine performance issues, not an external fuel leak.
  • C. An inoperative fuel gauge sender would affect the fuel level display, not cause a gasoline leak.

Fuel System Leak Symptoms

Symptoms of a fuel system leak include a strong gasoline odor, visible fuel drips or puddles, and potentially a decrease in fuel economy.

  • Strong gasoline smell is a primary indicator.
  • Visible fuel on the ground confirms a leak.
  • Leaks can occur in lines, tank, or injectors.

Memory trick: Smell Gas, See Puddle, Find the Source.

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